<!DOCTYPE html>
<p>There should be a blue square below.</p>
<div style="-webkit-columns:2; -webkit-column-gap:0; column-fill:auto; width:4em; height:6em;">
    <div style="position:relative;">
        <div style="-webkit-column-break-after:always; height:4em; background:blue;"></div>
        <div style="position:absolute; width:100%; height:4em; background:blue;"></div>
    </div>
</div>
